From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:45231) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WrqNG-0004Vv-Er for qemu-devel@nongnu.org; Tue, 03 Jun 2014 11:11:48 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WrqN6-0006H3-Sq for qemu-devel@nongnu.org; Tue, 03 Jun 2014 11:11:38 -0400 Received: from e06smtp16.uk.ibm.com ([195.75.94.112]:59370) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WrqN6-0006Gu-K8 for qemu-devel@nongnu.org; Tue, 03 Jun 2014 11:11:28 -0400 Received: from /spool/local by e06smtp16.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 3 Jun 2014 16:11:27 +0100 Received: from b06cxnps4075.portsmouth.uk.ibm.com (d06relay12.portsmouth.uk.ibm.com [9.149.109.197]) by d06dlp02.portsmouth.uk.ibm.com (Postfix) with ESMTP id 573A32190041 for ; Tue, 3 Jun 2014 16:11:15 +0100 (BST) Received: from d06av04.portsmouth.uk.ibm.com (d06av04.portsmouth.uk.ibm.com [9.149.37.216]) by b06cxnps4075.portsmouth.uk.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id s53FBPhO21758110 for ; Tue, 3 Jun 2014 15:11:25 GMT Received: from d06av04.portsmouth.uk.ibm.com (localhost [127.0.0.1]) by d06av04.portsmouth.uk.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id s53FBPUF018873 for ; Tue, 3 Jun 2014 09:11:25 -0600 Date: Tue, 3 Jun 2014 17:11:23 +0200 From: Cornelia Huck Message-ID: <20140603171123.49fb8b8f.cornelia.huck@de.ibm.com> In-Reply-To: <1401448669-4655-1-git-send-email-stefanha@redhat.com> References: <1401448669-4655-1-git-send-email-stefanha@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v3 0/8] virtio-blk: use alias properties in transport devices List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Stefan Hajnoczi Cc: pbonzini@redhat.com, peter.crosthwaite@xilinx.com, fred.konrad@greensocs.com, qemu-devel@nongnu.org, afaerber@suse.de On Fri, 30 May 2014 13:17:41 +0200 Stefan Hajnoczi wrote: > v3: > * Split qdev_alias_all_properties() into its own patch [Peter Crosthwaite] > * Do not dereference DEVICE_CLASS(class) inline [Peter Crosthwaite] > > v2: > * Add qdev_alias_all_properties() instead of virtio-blk-specific function [Paolo] > * Explain refcount handling in doc comment [Paolo] > * Fix "property" duplicate typo [Peter Crosthwaite] > * Add "the same object or" to clarify commit description [Igor] > > Thanks for the feedback on the RFC. This time around the alias property is > implemented at the QOM property level instead of at the qdev property level. > > Note that this series only addresses virtio-blk. In later series we can > convert virtio net, scsi, rng, and serial. > > The virtio transport/device split is broken as follows: > > 1. The virtio-blk device is never finalized because the transport devices > (virtio-blk-pci and friends) leak the refcount. > > 2. If we fix the refcount leak then we double-free the 'serial' string property > upon hot unplug since its char* is copied into the virtio-blk device which > has an identical 'serial' qdev property. > > This series solves both of these problems as follows: > > 1. Introduce a QOM alias property that lets the transport device forward > property accesses into the virtio device (the child). > > 2. Use alias properties in transport devices, instead of keeping a duplicate > copy of the VirtIOBlkConf struct. > > 3. Fix the virtio-blk device refcount leak. It's now safe to do this since the > double-free has been resolved. > > Tested that hotplug/hotunplug of virtio-blk-pci still works. FWIW: I gave your qom-alias-property branch a quick test on s390. virtio-ccw: seems to work fine, hotunplug of virtio-blk-ccw is still fine, and the virtio-blk memory leaks due to missing finalization that valgind complained about are gone. s390-virtio: still boots, but with x-data-plane=on we get the predictable segfault in virtio_blk_data_plane_start() since s390-virtio doesn't do notifiers. Maybe the dataplane code should do a quick check for existence of the notifier callback when it allocates the dataplane structure? > > Stefan Hajnoczi (8): > qom: add object_property_add_alias() > virtio-blk: avoid qdev property definition duplication > virtio-blk: move x-data-plane qdev property to virtio-blk.h > qdev: add qdev_alias_all_properties() > virtio-blk: use aliases instead of duplicate qdev properties > virtio-blk: drop virtio_blk_set_conf() > virtio: fix virtio-blk child refcount in transports > virtio-blk: move qdev properties into virtio-blk.c > > hw/block/virtio-blk.c | 18 +++++++++------ > hw/core/qdev.c | 21 +++++++++++++++++ > hw/s390x/s390-virtio-bus.c | 10 ++------ > hw/s390x/s390-virtio-bus.h | 1 - > hw/s390x/virtio-ccw.c | 7 ++---- > hw/s390x/virtio-ccw.h | 1 - > hw/virtio/virtio-pci.c | 7 ++---- > hw/virtio/virtio-pci.h | 1 - > include/hw/qdev-properties.h | 2 ++ > include/hw/virtio/virtio-blk.h | 19 --------------- > include/qom/object.h | 20 ++++++++++++++++ > qom/object.c | 52 ++++++++++++++++++++++++++++++++++++++++++ > 12 files changed, 112 insertions(+), 47 deletions(-) >